About
This small, perennial herb is notable for its unique, thread-like leaves that unroll in spirals, a pattern similar to circinate vernation seen in ferns. *Drosera filiformis* is commonly known as Tracy's sundew or dewthread.
Field notes
Morphology
The plant forms a rosette with long, erect, filiform (thread-like) leaves that unroll in spirals.
Distribution & habitat
It occurs naturally along the eastern seaboard of North America, ranging from south western Nova Scotia down through New England to Florida, and also on the Gulf Coast from Florida to Louisiana.
Cultivation notes
It requires mineral-poor soil and distilled, reverse osmosis, or collected rain water, and must undergo a winter dormancy, forming hibernacula for long-term survival.
Conservation
It is a Schedule 1–listed endangered species of Canada under the Species at Risk Act, though it is considered range-wide to be of 'least concern' by the International Union for Conservation of Nature. Threats include development, peat mining, and competition from shrubs.
Habitat
- Altitude
- 0–200 m
- Altitude class
- lowland
- Native to
- United States
Cultivation
- Difficulty
- intermediate
- Temperature
- Summer 22–30°C / Winter dormancy -5–10°C
- Humidity
- 50–80%
- Notes
- Long thread-like leaves. Forms winter hibernacula.